1996 Ford F250, 7.3 diesel. Steering column has been loose for a bit, which makes me suspect the switch.....Started truck fine to come home from work. Pulled into driveway and as soon as I turned the key to off, the starter started turning over. Turned the switch back to on, engine ran, starter stopped. Thought it might be the loose column, jiggled it around to no avail. Kept shutting the switch off, still ran the starter, finally, POOF, big puff of smoke out from under the hood, and it quit. Now, no starter. Thinking it could possibly be the solonoid, although it is new.....really not looking forward to tearing into the column and the switch!